Seal for rotatable closure plate on transit type concrete mixers



April l8, 1950 A. J. PASQUARIELLO 2,504,223

SEAL FOR ROTATABLE CLOSURE PLATES 0N TRANSIT TYPE CONCRETE MIXERS Filed Nov. 14, 1949,

ARMAND J. PASQUARIELLO IN VEN TOR.

Patented Apr. 18, 1950 "UNITED STATES Application November 14, 1949, Serial No. 127,110

1.0laim. 1

This invention relates generally to concrete mixing apparatus of the transit type such as truck mixers and more particularly'to a sealin structure betweenthe rotating and "non-rotating portions of the closure means provided thereon.

It will be understood that while this invention is described in connection with transit type concrete mixers, that it is applicable toany type of concrete mixer wherein the closure means has a rotatable and a non-rotatable portion.

Truck mixers, as the transit type concrete mixers are conventionally called, are utilized principally for rapidly transporting concrete or the ingredients therefor some distance away fromthe initial mixing point. They usually comprise a mixing drum rotatably mounted on a-truck chassis with suitable means adapted for rotating "the mixer, and elevated axial opening at the rear end of the mixer being used both for loading and for discharging the mixing drum, special 'blading within the drum effecting the mixing when the drum is rotated in one direction and election of the material when the "drum is rotated in the opposite direction.

In the prior art, onetypeofclosuremeanslfor the axial opening-comprises acombined hargin'g hopper and closure whereinthezclosureis usually a plate-like member which cooperates with 'a seat around the axial opening in the drum. vItis preferred to have the "charging hopper so arranged that it maybe swungaway from the mix?- ing drum forthe purposevof discharging the drum.

and accordingly it is'usuall'y mounted on-suitable framing and is not rotatable with the mixing drum. Thus, the closure. plate-may be either fixedly connected to the-charging hopper or it may be rotatably connected to the charging :hopper, seating itself in any suitable manner. In the latter case it-will rotate with the mixing; drum when .it is in operation.

It is with this latter type of closure platsthat the present invention deals. With. this type of rotatable closure plate a movable surface is created between the rotatable closureplate and the non-rotatable charging hopper which must be provided with a suitable: seal to prevent leakage from the mixing drum and wear between the rotating surfaces.

Accordingly, it is an objector thepresentinvention to provide .a seal'betwe'en, the rotatable closureplate andthenon-rotatable charging hopper on a transit concrete mixer.

It is another object of the present invention to. provide a. seal which is easily accessible and may be easily changed whenit needs'replacement.

It is a further object of the present invention to provide a seal which will. be kept free of dirt and other foreign matter and which .can be easily lubricated to "provide a substantially frictionless surface.

With this and other-objects in view as may appear from the accompanying specification, the invention consists of various features of construction and-combination of parts which will be first describedin connection with the accompanyingdrawings showing a seal for "charging hopper and rotatable closure-plate on transit type concrete mixers of a preferred form embodying the invention, andthe features forming the invention will be specifically pointed out in the claim.

In the drawings- Figure 1 is a side elevation of the discharge end of a transit type concrete mixer showing the invention in section thereon.

Figure 2 is an enlarged vertical section of the invention.

Referring to the drawings, Figure 1 shows a fragment-of the mixing drum I and a frame 2 which are mounted on a main frame bolted to a truck chassis (notshown). Mounted to the frame 2, to oscillate to and away from-an axial opening t atthe end of the mixing :drum l, is a combined charging hopper and closure 4. The charging hopper and closure '5 is to provide easy means for both loading the mixing drum and closing the axial opening thereon during the mixing or transit of materials forming the concrete.

Axial opening 3 has an annular flange '5 formed thereon. Attached thereto by. suitable means is a second annular flange 6 formed on an annular member I. The outer portion of the member 1 away from the mixing drum 1 is provided with an annulartapered hp 8 which is engaged in valve-like seating arrangement by a dished closure plate 9, all of which "is clearly shown in Figurel ofthe drawings.

The closure plate 9 is connected to the discharge end of a funnel-shaped feed hopper, Ill by airotatablewsurfacebearing and support member i .i hereinafter described. The funnel-shaped feed hopper I will be constructed to provide unrestricted passage therethrough, an opening I2 of substantially the same diameter as the discharge end of the feed hopper ID being provided on the dished closure plate so that ingredients placed in the hopper will pass into the mixing drum I. The rotatable bearing and support member I I provides means for allowing the closure plate to rotate with the mixing drum when it is in operation as the weight of the charging hopper and closure will hold the convex surface l3 of the closure plate 9 in contact with the tapered lip 8 as is shown in Figure 1 of the drawmgs.

Rotatable surface bearing and support member The rotatable surface bearing and support member II comprises an annular outer seal ring I4 which is engaged by an annular inner seal ring I5 as hereinafter described. The outer seal ring I4 is fixedly connected to the discharge end of the feed hopper III by suitable means such as bolts I6 and nuts I1, and the inner seal ring [5 which engages the outer seal ring I4 is in turn connected to the dished closure plate 9 by suitable means such as bolts !8 and nuts I9, all of which is clearly shown in Figure 2 of the drawings.

Outer seal ring I4 forms one surface of the rotatable surface bearing and support member H. It has a substantially fiat annular rim shape being connected on the inner end thereof to the discharge end of the feeding hopper as above stated. In the medial portion of the rim a side member extends inwardly towards the axial opening 3 of the mixing drum at a substantially right angle to the rim portion of the seal ring I lv An annular groove 2| and a shoulder 22 are formed on the outer surface of the side arm 20 whereby an inner annular projection 23 is formed on the axial opening side of the annular groove 2i and an outer annular projection 24 is formed on the side of the annular groove 2| closest to the discharge end of the feed hopper as is clearly shown in Figure 2 of the drawings.

The inner seal ring I5 forms the other surface of member I I and is also a substantially fiat rimlike member which has a flange 25 constructed and shaped to snugly engage the annular groove 2I and those portions of the inner and outer annular projections 23' and 24 adjacent thereto. An annular insert 26 is formed in the inner seal ring I5 and forms substantially a continuation of the shoulder 22 on the outer seal ring I4. This insert 26 will provide means for fixedly connecting the sealing means 21 to the dished closure plate 9.

Inner seal ring I5 and the outer seal ring l4 as above described, form the rotatable surfaceto-surface bearing for the closure member 9 and act to support member 9 so that it will be movable with the feeding hopper I0 thus forming the combined charging hopper and closure 4 above mentioned.

Sealing means The sealing means 2'! is a flat annular member preferably of a resilient material although any similar type gasket material of which there are many well known types on the market may be utilized for this purpose. A portion thereof is firmly held in the insert 26 between the inner seal ring I5 and the dished closure plate 9 whereby it will be rotatable therewith. The dished closure plate 9 extends .up past the sealing means 21 on the axial opening side thereof, acting to enclose the sealing means 21 and to reduce the amount of contacting area with the ingredients passing through the charging hopper and closure 4.

Thus when the inner seal ring I5 is in engagement with the outer seal ring I4, the portion of the sealing ring which is not held by the insert will extend up and engage the shoulder 22 on the outer seal ring I4 in surface-to-surface relationship and in this position will lie adjacent the rotatable surface bearing and support member I I. That portion of the closure plate 9 which extends past the sealing means abuts the end of the side member 20 leaving a line-like opening 28 as the only opening through which the ingredients passing through charging hopper and closure 4 may contact the sealing means 2'! thus aiding the sealing means to prevent grit or foreign matter from passing to the adjacent bearing and support structure I I, as is clearly shown in Figure 2 of the drawings.

Since the above described members forming the rotatable surface bearing and support member I I, and the sealing means are in surfaoe-to-surface engagement, lubrication means is provided therefor. A passage 29 being provided in the side member 20 extending to the outer side thereof. An Alemite lubrication fitting 3O threadably engages the outer end of this passage whereby lubricant may be forced into the passage 29 by any suitable means. The other end of the passage 29 communicates with a transverse passage 3| formed in the inner projection 23 and opening at the point where surface-to-surface contact is made between the outer and inner seal rings I4 and I5 whereby lubricant will pass along these surfaces and diffuse outwardly therefrom to the other portions in surface-to-surface engagement such as the sealing means 2'! and the shoulder 22.

In operation, the charging hopper and closure 4 is manually moved by handle 32 towards the axial opening 3 until the convex surface I3 of the closure plate 9 comes into snug contact with the tapered lip 8. The mixing drum I is then loaded and the concrete mixed by rotation of the drum.

I As the drum rotates, the closure plate will rotate therewith in the rotatable surface bearing and support structure II above described. The linelike opening 28 allows only a minimum contact between the ingredients and the sealing means 21 and the sealing means prevents any grit or other foreign matter from passing down the shoulder 22 which it engages during rotation into the rotatable surface bearing and support member II.

When it is desired to change the sealing means, all the operator need do is oscillate the charging hopper or closure 4 outwardly till it clears the axial opening and then loosen bolts I9 and remove the dished closure plate 9. The sealing means 21 is now easily removable and may then be replaced by a new member.

It will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown, but that they may be widely modifiedwithin the invention defined by the claim.

What is claimed is:

In a combined charging hopper and closure for the axial opening of the mixing drum on a transit type concrete mixer, a feeding hopper having an open unrestricted discharge, an outer seal ring fixedly connected to said feeding hopper, an annular groove formed in said outer seal, a rotatable closure plate'adapted to sealingly engage said axial opening of 'themixing drum and to revolve The following references are of record in the REFERENCES CITED file of this patent:

UNITED STATES PATENTS Number Name Date Barnes May 1, 1945 Peters Nov. 30, 1948 

